Tuesday, August 7, 2007 - 3:20 PM

COS 58-6: Effects of UV-B in freshwater and marine organisms: A synthesis through meta-analysis

Betsy A. Bancroft, Oregon State University

Ultraviolet-B radiation (UVB) is a global stressor with potentially far-reaching ecological impacts.  In the first quantitative analysis on the effects of UVB on aquatic organisms, meta-analytic techniques were used to explore the effects of UVB on survival and growth in freshwater and marine systems.  I predicted that UVB would have different effects in different habitats, experimental venues, trophic groups and life history stages. Contrary to the predictions, an overall negative effect of UVB was observed on both survival and growth that crossed life histories, trophic groups, habitats and experimental venues.  In the survival analyses, no relationship between mean effect size and taxonomic groups or levels of exposure to UVB was detected. UVB had larger negative effects on growth in embryos compared with later life history stages. In the growth analyses, a larger negative effect on protozoans was observed.   These analyses suggest that the effects of UVB in aquatic systems are large and negative but highly variable between organisms.  Variation in susceptibility may have important implications for population and community structure.